Field of Invention
The present invention generally relates to a ternary content addressable memory (TCAM), and more particularly to a TCAM with fewer circuit components.
Description of Prior Art
A content addressable memory (CAM) has a plurality of memory cells for storing stored data. Furthermore, the content addressable memory can receive search signal, and compares the search signals with stored data of selected memory cell. If the stored data of selected memory cell and the search signal are the same, a search result is match, and if the stored data of selected memory cell and the search signal are different, a search result is miss. That is, a search 1 operation or a search 0 operation can be operated on the CAM. The search 1 operation is used to search whether the stored data of the selected memory cell is 1 or not, and the search 0 operation is used to search whether the stored data of the selected memory cell is 0 or not.
On the other hand, a ternary content addressable memory (TCAM) is also provided in conventional art. Different from the CAM, the TCAM can also operates a search don't care operation. When the search don't care operation is operated on the selected memory cell, the stored data would not be compared with the search signal, and the search result is always match.